The present invention relates to a method for transferring crop material from a harvesting machine to a hauling vehicle, with which the crop material is accelerated and ejected through a conveying shaft of a transfer device to a target point on the transport vehicle.
The present invention also relates to a corresponding control unit for a harvesting machine, and a harvesting machine, in particular a forage harvester, with a transfer device and a control unit of this type.
Self-propelled harvesting machines, such as forage harvesters, combine harvesters or the like typically include a transfer device, e.g., with an upper discharge chute or a grain tank unloading tube, with which the crop material is transferred from the harvesting machine to a transport vehicle. When the harvested crop material is to be transferred continually during the harvesting operation, as is typically the case with a forage harvester, for example, the transport vehicle must be driven parallel alongside or behind the harvesting machine during the harvesting operation. To this end, a part of the conveyor chute of the transfer device that is attached to the outside of the machine—i.e., the upper discharge chute on a forage harvester—can be positioned by swiveling it around the vertical and horizontal axes such that the ejected or outflowing stream of crop material strikes the desired target point on the transport vehicle.
The transport vehicle typically must be driven behind the forage harvester the first time a forage harvester drives onto the field to be harvested, because there is no space next to it for the transport vehicle. As soon as a first track in the field has been harvested, the transport vehicle can be driven next to the forage harvester. Depending on the particular position of the transport vehicle relative to the harvesting machine, the transfer distance, i.e., the distance between the harvesting machine and the target point on the transport vehicle struck by the stream of crop material, naturally varies. Depending on the transfer distance, the crop material sometimes must be ejected less far and sometimes further out of the conveyor chute. When the transport vehicle is driven next to the harvesting machine, it is sufficient, e.g., for the crop material to simply fall downward out of the conveyor chute, since the conveyor chute typically extends over the transport vehicle. If the transport vehicle is driven behind the harvesting machine, however, a relatively long distance from the discharge end of the conveyor chute to the target point on the transport vehicle must be covered, e.g., to pass over a tractor that pulls a hauling trailer. A relatively rapid, “piercing” stream of crop material is ejected from the conveyor chute, so that the relatively lightweight crop material reaches the target point without significant losses and without being scattered by the wind and lost. To bring the crop material up to the necessary speed, it must be accelerated accordingly. This acceleration is carried out anyway by the processing units, e.g, in the case of a forage harvester, the chopper drum and any conditioning devices that may be present, such as the corn cracker. These working units simultaneously serve to convey the flow of crop material inside the harvesting machine at a certain speed. The speed attained by the working units is typically not adequate to convey the crop material through the conveyor chute and, in particular, over a long distance through the air as a fast-moving stream of crop material. Forage harvesters, for example, are therefore typically equipped with a post-accelerating device located in the entrance to the conveyor chute or directly in front of the conveyor chute.
An example of a post-accelerating device of this type is described in EP 1 380 204 A1. In a post-accelerating device of this type, the crop material is always accelerated to a speed that enables it to be transported out of the conveyor chute and through the air, even over a long distance. The exact trajectory is set by adjusting the height of the upper discharge chute and by adjusting a discharge flap located on the end of the upper discharge chute, by way of which the ejected stream of crop material is pointed in the desired direction toward the target point. A relatively great deal of energy is used to further accelerate the crop material.